8 Responses. > 1  the Moon takes an elliptical path around the Earth. The planets make nearly elliptical orbits around the Sun, close enough for reasonable approximations, but the Moonâs Orbit around the Earth is sufficiently influenced by the Sun that it follows a path detectably different from an ellipse.
Quick Answer. In 1896, French scientist Antoine Henri Becquerel discovered radioactivity which was an early contribution to atomic theory. He discovered this phenomenon while experimenting with uranium and a photographic plate. Continue Reading.
Cavendish also discovered the gas from a certain metal-acid experiment that he performed. Antoine Lavoisier named the gas hydrogen in 1783 when he and Pierre-Simon Laplace proved the findings of Cavendish that water could be produced when the gas is burned. The element was first liquefied in 1898 by James Dewar. He did this with the use of a vacuum flask and the regenerative cooling technique Dewar invented.